Light cones and repulsive gravity

Contrary to common belief, gravitation can also be repulsive. Examples of repulsive gravity are provided by the naked singularity solutions of the Einstein equations corresponding to the negative mass Schwarzschild, the Reissner–Nordström, and the Kerr spacetimes. We show that their repulsive gravity regions can be identified by a particular behavior of the light cones when use is made of symmetry-adapted coordinate systems

Coalescing binary systems of compact objects: Dynamics of angular momenta

The end state of a coalescing binary of compact objects depends strongly on the final total mass M and angular momentum J. Since gravitational radiation emission causes a slow evolution of the binary system through quasi-circular orbits down to the innermost stable one, in this paper we examine the corresponding behavior of the ratio J/M^2 which must be less than 1(G/c) or about 0.7(G/c) for the formation of a black hole or a neutron star respectively. The results show cases for which, at the end of the inspiral phase, the conditions for black hole or neutron star formation are not satisfied. The inclusion of spin effects leads us to a study of precession equations valid also for the calculation of gravitational waveforms.Comment: 22 pages, AASTeX and 13 figures in PostScrip

Psychometric properties of the Italian body shape questionnaire: an investigation of its reliability, factorial, concurrent, and criterion validity

PURPOSE: This study was set up to investigate the reliability, factorial, concurrent, and criterion validity of the Italian version of the 34-item Body Shape Questionnaire (BSQ) and its shorter versions. METHODS: The study included 231 patients diagnosed with an eating disorder and 58 putatively healthy people (comparison sample). The Italian BSQ-34 was administered to participants together with the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale. Information on body mass index, caloric intake at baseline, and the number of episodes of self-vomiting per week was also acquired. RESULTS: Cronbach’s alpha of BSQ-34 was 0.971 (95% confidence interval [CI] 0.965–0.976) in patients and 0.960 (0.944–0.974) in controls. Test–retest stability in patients (n = 69), measured with intraclass correlation coefficient, was 0.987 (0.983–0.991). Confirmatory factor analysis of the single-factor model yielded acceptable fit for all versions of the BSQ. On all BSQ versions, patients scored higher than controls with a large effect size when calculated as Cliff’s delta. BMI and mean caloric intake at baseline had a stronger association with BSQ-34 than levels of anxiety and depression. The analysis with the receiver operating characteristics (ROC) curve showed that the BSQ-34 distinguished patients with an eating disorder from controls with good accuracy (Area Under the Curve = 86.5; 95% CI 82.2–90.7). CONCLUSION: The Italian version of the BSQ possesses good psychometric properties, in both the long and the shortened versions, and it can be applied to measure body dissatisfaction for both clinical and research purposes. LEVEL OF EVIDENCE: Level III, Evidence obtained from well-designed cohort or case–control analytic studies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40519-022-01503-6

Multimode Trapped Interferometer with Ideal Bose-Einstein Condensates

We experimentally demonstrate a multi-mode interferometer comprising a Bose-Einstein condensate of $^{39}$K atoms trapped in a harmonic potential, where the interatomic interaction can be cancelled exploiting Feshbach resonances. Kapitza-Dirac diffraction from an optical lattice coherently splits the BEC in multiple momentum components equally spaced that form different interferometric paths, closed by the trapping harmonic potential. We investigate two different interferometric schemes, where the recombination pulse is applied after a full or half oscillation in the confining potential. We find that the relative amplitudes of the momentum components at the interferometer output are sensitive to external forces, through the induced displacement of the harmonic potential with respect to the optical lattice. We show how to calibrate the interferometer, fully characterize its output and discuss perspective improvements.Comment: 7 pages, 6 figure

Quick identification of the risk of psychosis: the Italian version of the prodromal questionnaire-brief

Background: Diagnosing people during the prodromal phase of an incipient psychosis can improve the chance of better outcome. In busy clinical settings, the ideal tool is a brief, easy-to-complete self-report questionnaire. Objective: To test the psychometric properties of the Italian version of one of the most used screening tools for the identification of the risk of psychosis, the Prodromal Questionnaire-Brief (PQ-B). Methods: Cross-sectional design. A convenience sample of college students was enrolled via snowball procedure (n=243; men: 45%). After understanding and signing the consent form, the participants received a booklet containing the following questionnaires: the 21-item Prodromal Questionnaire-Brief (PQ-B); the 12-item General Health Questionnaire (GHQ-12), and the 74-item Schizotypal Personality Questionnaire (SPQ). Receiver operating characteristic (ROC) analysis was used to assess the capacity of the PQ-B to identify individuals at risk of psychosis as independently defined based on the combination of GHQ-12 and SPQ thresholds. Results: The Italian version of the PQ-B revealed good internal consistency, test-retest reliability, and adequate convergent and divergent validity. The Youden method retrieved a cut-off = 7 for the PQ-B frequency score and a cut-off = 22 for the PQ-B distress score. Both PQ-B scores had a perfect (99%) negative predictive value. Conclusion: The PQ-B is a promising screening tool in two-stage protocols. The major advantage of the PQ-B is to exclude cases that are unlikely to be at risk of psychosis

The prevalence of specific phobia by age in an Italian nationwide survey: How much does it affect the quality of life?

Introduction: The study aimed to see if a community survey conducted by clinical interviewers with semi-structured psychiatric interviews shows lifetime prevalence rates of Specific Phobia (SP) similar to those found by surveys carried out by lay interviewers and if the high level of impairment found in SP may be confirmed. Methods: This is a community survey on an Italian nationwide sample randomly selected from registers of municipalities. Tools: semi-structured ANTAS psychiatric interview derived from the SCID-DSM-IV, carried out by clinicians (psychologists or physicians); Short Form Health Survey (SF-12) as a measure of Quality of Life (QoL). Analyses: means of the χ2 test odds ratios were adopted to test several associations regarding SP prevalence. One-way ANOVA was used to compare different groups on attributable burden due to SP and/or other disorders in worsening QoL. Results: The lifetime prevalence of SP was 2.3%. No difference was found by age class. Females showed more than twice the frequency of males (p<0.0001). The disorders showing the closest association with SP were: social phobia (OR=17.53); general anxiety disorder (OR=11.57); anorexia (OR=11.13) and agoraphobia (OR=10.03), but also obsessive compulsive disorders (OR=8.8), eating disorders (OR=7.2), panic disorder (OR=5.9), post-traumatic stress disorder (OR=5.8), and major depressive disorder (OR=4.8) presented an association that achieved statistical significance. The QoL of people with SP and at least one disorder of anxiety, mood or eating in comorbidity, measured as a score at SF12, was worse than controls without SP (p <0.001) but that of people with SP without co-morbidity was not (p = 0.809). Conclusion: An epidemiological study conducted by clinical interviewers through semi-structured interviews appears to re-dimension the impact of SP, at least from the public health perspective. Future prospective studies will better clarify the role of SP in the context of anxiety disorders

The impact of MDQ positivity on quality of life impairment: Does it support the hypothesis of Dysregulation of Mood, Energy, and Social Rhythms Syndrome (DYMERS)?

Background: DSM-5 separates bipolar (BD) from depressive disorders, but some experts consider BD as part of a spectrum of mood disorders. The interpretation of numerous false positives of BD screened by the Mood Disorders Questionnaire (MDQ) is part of this debate. Recent study results suggest that the worsening of health-related quality of life (H-Qol) associated with MDQ positivity does not depend solely on mood disorders. This study aims to clarify whether the impairment may be due to other concomitant disorders, unrelated to mood disorders, leading to a worsening of H-Qol. Additionally, the study aims to explore if MDQ positivity itself observe clinical significance.Design and methods: The study involved pairs of cases (MDQ+) and controls (MDQ-) matched for sex, age, and absence of DSM-IV psychiatric comorbidity. The impact of MDQ positivity on the quality of life in a sample of MDQ+ comorbid with MDD was measured and compared to impact of MDD in other chronic disorders.Results: The H-Qol was significantly worse in MDQ+ than in controls (both groups without any psychiatric co-morbidity). The worsening was similar to severe chronic disorders The burden of worsening quality of life due to MDD was mild in another sample of MDQ positives with comorbid MDD.Conclusion:The study hypothesizes that MDQ positivity may be related to hyperactivation and dysregulation of rhythms typical of stress disorders. In fact, MDQ+ was found strongly related to sleep disturbances. Future studies could verify if a "Dysregulation of Mood, Energy, and Social Rhythms Syndrome" (DYMERS), causes worsening the H-Qol in MDQ+